Certain polymer-iron complexes for treatment of iron deficiency

ABSTRACT

The present invention relates to a process for preparing a polymer which is suitable for being administered parenterally from a saccharide, a polyhydric alcohol and a polymerization agent and to the polymer prepared therefrom. The invention relates also to an iron preparation suitable for parenteral intramuscular and intravenous - injection, to a process for the preparation of the iron preparation, and to the use of the injectable iron preparations in human and veterinary medicine.

United States Patent [1 1 Dahlberg et al.

[ CERTAIN POLYMER-IRON COMPLEXES FOR TREATMENT OF IRON DEFICIENCY [75] Inventors: Alf-Goran Dahlberg, Nykvarn; Karl Gustav Hogberg, Sodertalje; Sven Lindvall, Sodertalje; There Oskar Verner Rydh, Sodertalje, all of Sweden [73] Assignee: Astra Lakemedel Aktiebolag,

Sodertalje, Sweden [22] Filed: Mar. 22, 1973 [21] Appl. No.: 343,690

[30] Foreign Application Priority Data Sept. 13, 1972 South Africa.....................n 72/6255 [52] US. Cl. 424/180; 260/209 R; 260/2l0 R; 260/635 C; 424/78 [51] Int. Cl. A61K 31/70 [58] Field of Search 424/180, 295, 78;

[56] References Cited UNlTED STATES PATENTS 3,275,576 9/1966 Flodin et al 260/2") R Dec. 23, 1975 OTHER PUBLICATIONS Chemical Abstracts, Vol. 77 (1972), p. 66l93m (Swedish App., Dec. 1968).

Primary ExaminerV. D. Turner Attorney, Agent, or Firm-Brambaugh, Graves, Donohue & Raymond ABSIRACT preparation suitable for parenteral intramuscular and intravenous injection, to a process for the preparation of the iron preparation, and to the use of the injectable iron preparations in human and veterinary medicine.

19 Claims, No Drawings CERTAIN POLYMER-IRON COMPLEXES FOR TREATMENT OF IRON DEFICIENCY BACKGROUND or THE INVENTION ln the treatment of iron deficiency in mammals, including man, iron may be administered orally with subsequent resorption via the alimentary canal, or parenterally by introvenous or intramuscular injection of a solution containing iron. in such solutions for parenteral administration, the iron must be present as ferric iron in a stabilized form in order to prevent gel formation and precipitation, for example, precipitation of ferric hydrate at physiological pH. The iron must also be present in such a form that no toxic side reactions, whether of a local or of a general type, occur when injecting dosages containing at least l() mg. of iron. Solutions of salts of iron cannot be used for parenteral administration mainly because of their relatively high toxicity.

Various substances have previously been used as stabilizing agents in iron preparations for parenteral administration. In order to prevent precipitation of ferric hydrate by alkalization of an aqueous solution of a ferric salt solution, some kind of carbohydrate was heretofore early used as a stabilizing agent. Thus, one prior preparation for parenteral administration consisted essentially of an aqueous solution of a saccharated oxide of iron. However, in order to prevent precipitation of ferric hydroxide the pH of this iron preparation had to be alkaline, and parenteral administration of the preparation often led to undesirable side effects.

Other types of stabilizing agents previously used in preparations of iron for intramuscular injection are dextrins and dextrans; The use of dextrins and dextrans made it possible to prepare injection solutions with a physiological pH. However, preparations containing a complex of low molecular weight dextran and iron have resulted in undesirable side effects, such as local pain and discoloration of the skin surrounding the site of the injection [Acta Medica Scandinavica Suppl. 342 T. Karlefors and A. Norden Studies on iron-dextran complex (l968)]. Dextrin, a degraded starch, contains reducing groups which may reduce some ferric iron in the iron preparation to ferrous iron. Presence of ferrous iron in the preparations is undesirable and a limiting factor which. because of its toxicity, may give rise to side effects when administered in high dosages.

Still another type of stabilizing agent used in the preparation of iron preparations for intramuscular administration is a combination of sorbitol, citric acid and dextrin (Canadian Pat. No. 659,420). It was found that such a combination of sorbitol, citric acid and dextrin could be used to stabilize ferric iron so that an iron complex with an average molecular weight of about 5000 was obtained, whereas the previously used irondextran and iron-dextrin complexes had average molecular weights exceeding l( ,()0(). The acute toxicity, LD 50, of this complex of iron for intra-peritoneal administration to mice was about 50 mg per kg bodyweight, which toxicity, although higher than the toxicity of the iron-dextrin and iron-dextran preparations, still made possible administration of humans of dosages not exceeding 200 mg. of iron. Thus, a large number of injections to a single patient is necessary. The iron in this preparation, sold under the trade name .lectofer", is present, in the form of particles of such small size that they are rapidly resorbed via both the lymphatic 2 vessels and the blood vessels. The small size of the particles and the comparatively low average molecular weight also mean, however, that about 30% of the administered amount of iron is excreted via the kidneys. The remaining part of the administered iron is utilized to a very high degree at the hematopoiesisv Thus, it would be advantageous to have a stabilizing agent which results in relatively low losses of adminis tered iron. via the kidneys and lower toxicity permitting administration to humans of single dosages containing more than 200 mg. of iron.

It would also be advantageous to avoid the presence of reducing groups in the dextrin which may convert part of the ferric iron to ferrous iron. As stated above, previously used stabilizing agents in iron preparations for intramuscular injection contain sugar or polymers of sugar, such as dextrin or dextran, which have a stabilizing effect on a ferric colloid at neutral pH. These previously used stabilizing agents commonly contain reducing groups which to some degree convert ferric iron in the injection solution to ferrous iron. Ferrous iron is an undesired component in iron preparations for intramuscular injection due to its toxicity and may cause undesired side effects at administration of the solutions to the patients. The amount of ferrous iron present in the injection solution may, due to its toxicity, constitute a limiting factor for the maximum dosage of iron which may be administered to the patient in each injection.

SUMMARY OF THE INVENTION A main object of this invention is to provide an iron preparation for intramuscular administration which contains, as stabilizing agent, a new polymer which l. has the capability to stabilize ferric iron at physio logical pH,

2. causes an insignificant reduction of ferric iron to ferrous iron in an injection solution,

3. has the capability to yield a complex with ferric iron which has a low toxicity and after intramuscular injection is resorbed to a high degree from an intramuscular depot while only a minor part is excreted via the kidneys, and

4. has capability to yield a complex with ferric iron which has such toxicity that a dosage of more than 500 mg of iron may be administered to humans without serious side effects.

Thus, in accordance with this invention, these objects have been met with new iron preparation which is well resorbed and which has a low toxicity making administrations of unit dosages containing more than 500 mg iron possible without serious side effects. Although the main use of the new polymer used as stabilizing agent is in the preparation of iron preparations for intramuscular administration, other fields of use are apparent as described herebelow.

The present invention provides an iron preparation for intramuscular and intravenous injections which contains, as stabilizing agent, a physiologically innocuous, water swellable polymer which is a product prepared from a saceharide, and a polyhydric alcohol with a polymerizing agent selected from the group consisting of halogenated aliphatic alcohols transformable to epoxides in alkaline solution, the epoxides obtained thereby and mixtures thereof.

DETAILED DESCRIPTION OF THE INVENTION The saccharides suitable for this invention are Sucrose, trehalose, rafi'mose and mixtures thereof. The preferred compound is sucrose.

The term polyhydric alcohol as defined herein is at least one from a broad class of aliphatic alcohols containing 2 to l carbon atoms and 2 to [0 alcoholic hydroxyl groups. Besides such alcohols which solely contain non-etherified groups, polyhydric alcohol" further defined herein include those which are partially etherified ive. one or more but not all of the alcoholic hydroxyl groups may be etherified. For instance. the hydroxyl groups may be etherified with C to C alkyl groups or with C to C hydroxylalkyl groups. One such suitable partially etherified alcohol, among others. is hydroxy propyl sorbitoL Examples of polyhydric alcohols. among others, are glycerol and glycol with the structural formula:

; tetritols. e.g., compounds with the structural formula:

; pentitols. e.g., compounds with the structural formula:

H- .OH CH OH CH OH HOjH H%OH H OH H OH H H H OH H OH H OH H OH CH OH CH OH iH OH arahiml llyxitoll xylitnl rihitol (adoniloll hexitols. e.g.. compounds with the structural formula:

H. .OH CH OH H. .OH H. ,OH

H OH H H HO H H H H H HO H H H H OH H OH H OH H H HOfiH H OH H OH 1 :EQH H OH H .OH H OH H OH CH OH surhilol mannilol talitol idiml H =OH YH OH HTOH HCOH HOCH HCOH HO H HCOH HC'OH H('OH CH OH CH,()H

gulactitol allitul (dulicitoll heptitols, e.g., compounds with the structural formula:

(DB-Glycnhcptb tol) (a-Mannnheptitnl] ((iH- OH CH OH H. .OH CH OH HO H H OH H H H OH HOIH H H H OH HO H HCOH HCOH HOCH HJIOH H OH HCOH HO H HO H H OH H OH H OH H OH H OH H OH H OH CH- OH D-glycern-D- D-glyccro-D- Uglyccro-L- glycero idomanno gluco gluco heplitol heptitol hcptitol hcptitnl (meso) [Volem itol) (B-Sedo- (D-B-Gula- [D /3 Mannohcptitol) hcptitol l hcptitol) (D-a-Gulo (a-Sedo heptitol) hcptitol) octitols, nonitols and decitols, e.g.,

CH- -OH H OH H- .OH

H H H OH H OH H OH H OH H OH H OH H OH HOCH HO H HO H HO H H OH H OH H OH H OH H OH H OH (H-,OH H OH H OH D-erythr0l.- D-crythro-L- erythrnmannoguluoctitol talonctitnl nctitol Examples of other compounds within the definition of polyhydric alcohols, among others, are polyglycerols, e.g., condensation products of glycerol in which molecules of glycerol have been condensed to openchain or cyclic ethers such as ci-nOHCHOHCH,-o-cH,cHHc|-|,oH

and

Still further examples of polyhydric alcohols, among others, are pentaerytritol, the inositols or cyclohexanehexols.

Many of the aforementioned polyhydric alcohols occur in various steric configurations and in racemic form as well as in the form of optical isomers. As further defined herein, the term polyhydric alcohol" includes all such steric and optical isomers as well as mixtures thereof.

As defined herein for the polymerizing agent, the term halogenated aliphatic alcohols transformable to epoxides in alkaline solution" includes at least one compound illustrated by the following generic formula:

HCH,OH

wherein n is an integer selected from the group consisting of 0,l,2,3, and 4; X is selected from the group consisting of Cl, Br, and l; R is selected from the group consisting of OH, Cl, Br, and I; and R is selected from the group consisting of H, and if R is OH also the radical CH X, wherein X has the meaning specified above. The conversion of these alcohols to epoxides is known in the art [Fairbourne et al., J.P.O.S. pages l965-l973 (1932)].

These compounds (I) include, among others, compounds of the formula:

the compounds (II) in alkaline solution are converted to a diepoxide of the formula:

wherein n has the meaning specified above.

Other compounds (I) are dihalohydrins of the formula:

wherein X has the meaning specified above, and the compounds (Ill) in alkaline solution are converted to compounds of the formula:

CHo- H CH, X

wherein X has the meaning specified above.

Still other compounds (I) have the formula:

(Vll) wherein n has the meaning specified above.

Specific compounds (ll), among others, are those in which X is Cl and n is O, X is Cl and n is l and X is Cl and n is 2.

Specific compounds (lll), among others, are those in which n is 0, n is l and n is 2.

Specific compounds (IV), among others, are those in which both Xs are chlorine, both Xs are bromine and one X is chlorine and the other X is bromine.

Specific compounds (V), among others, are those in which X is chlorine, X is bromine and X is iodine.

Specific compounds (Vl), among others, are those in which X is chlorine and n is O, X is chlorine and n is l, X is bromine and n is O and X is bromine and n is l.

Specific compounds (VII), among others, are those in which n is O, n is l and n is 2.

The compounds (Ill), (V) and (VII) are, among others, illustrative examples of epoxides. [t is a common feature of polymerizing agents of the compounds (l)(Vll) that they contain at least two reactive groups capable of participating of formation of ether linkages. As further defined herein, the term epoxides" include, among other, diepoxides and epoxycarboxylic acids.

The preferred saccharide, as stated heretofore, is sucrose. Preferred polyhydric alcohols are glycerol, polyglycerol, the tetritols, the pentitols, the hexitols and the heptitols. Of the polymerizing agents, the epihalohydrins, particularly epichlorohydrin, are preferred.

The especially preferred combination of reactants is sucrose, sorbitol and epichlorohydrin. Other suitable combinations among others are: trehalose, sorbitol,

7 and epichlorohydrin, raffinose. sorbitol and epichlorohydrin; sucrose, pentaerytritol and epichlorohydrin; glycerol, sucrose and epichlorohydrin; mannitol, sucrose, and epichlorohydrin; dulcitol, sucrose and epichlorohydrin; and hydroxypropylsorbitol, sucrose and epichlorohydrin.

The polymer of the present invention may be prepared by any suitable method. One method is to react in a liquid medium at least one saccharide as defined above, at least one polyhydric alcohol as defined above and at least one polymerizing agent as defined above.

The polymerization is generally carried out in the presence of an alkali, e.g., alkali metal hydroxides. Sodium hydroxide or potassium hydroxide among others. may be used. The alkali may be used either in the form of a solution or in the solid state, for example, in the form of tablets. Alkaline earth metal hydroxides, such as, barium hydroxide, may also be used as the alkali. The preferred alkali is sodium hydroxide.

The polymerization may be carried out in a medium which is inert to the reactant solutions. Examples of such inert media are benzene and white mineral spirits. However, an aqueous solution is the preferred medium.

Any satisfactory proportions of the saccharide, the polyhydric alcohol and the polymerizing agent may be employed. Any satisfactory reaction temperature may also be employed and the reactants may be introduced by any suitable manner. For example, about 0.1 to about 1.0 moles of saccharide and about 0.05 to about moles of polymerizing agent per mole of polyhydric alcohol may be used. In a preferred embodiment of the invention, using sucrose, sorbitol and epichlorohydrin, from about 0.2 to about 1.0 moles of sucrose and from about 0. l to about 4 moles of epichlorohydrin per mole of sorbitol may be advantageously used.

It may be advantageous to carry out the polymerization by adding the alkali and the polymerizing agent separately to an alkaline aqueous solution of the sacc haride and the polyhydric alcohol. However, the alkali and polymerizing agent may also be added continu ously to the alkaline solution of saccharide and the polyhydric alcohol in the reaction vessel.

The reaction temperature may be varied over a wide range but is advantageously held between about C. and up to the boiling point of the reaction mixture. The preferred reaction temperature is about 75to 85C.

The amount of alkali present during the reaction will depend largely upon the amount of added polymerizing agent which is added. In a preferred embodiment ofthc invention where sorbitol and sucrose are polymerized with epichlorohydrin, the total amount of hydroxyl ions present during the reaction is from about 1.5 to 4.5 moles per mole sorbitol. In the preferred embodiment, sodium hydroxide is used as alkali.

in an especially preferred method for carrying out this reaction, a solution of sucrose and sorbitol in the approximate relative amounts of about 0. l to l .0 mole, preferably about 0.5 mole, of sucrose, per mole sorbitol is prepared and made alkaline by addition of sodium hydroxide. To this solution are separately added during the course of the reaction epichlorohydrin and sodium hydroxide in the approximate relative amounts of about 0.l to 4 moles, preferably about 2 moles, of epichlorohydrin per mole of sorbitol. The temperature of the reaction mixture is raised successively during the reaction up to the desired temperature, e.g., about 75 to 85C. After addition of the epichlorohydrin and the sodium hydroxide, the reaction solution is allowed to 8 stand for some time, whereafter the temperature is lowered to about 50C. and the pH ofthe reaction mixture is adjusted by addition of a suitable acid, such as HCl, to a value of about 0.6 to 4, usually about 0.65 to 1.0.

The sodium chloride precipitated in the method is removed by filtration and discarded. The remaining reaction mixture is worked up, i.e., subjected to repeated precipitation and redissolving of the polymer obtained. It is preferred to use ethanol as the precipitating agent, but other organic solvents, such as dioxane, methanol, chloroform, acetaone, n-propanol and isopropanol, among others, may be used. The addition of ethanol results in the formation ofa two-phase system. The aqueous phase contains the desired reaction product. The ethanol phase contains interalia such reaction products having a low molecular weight which are not precipitated. The aqueous phase containing the desired reaction product is thereafter again mixed with water and ethanol. and the resulting aqueous phase collected. This purification and fractionating procedure may be repeated several times, suitably at least five times, whereafter the final product which is the intermediate polymer is diluted with a suitable amount of water in order that a product which is easy to handle may be obtained.

The intermediate polymer, which may or may not be acidified to bring the aldehyde and keto groups into a more reactive state, is reacted with a cyanide to add cyanide ions to the aforementioned carbonyl groups in the intermediate polymer thereby forming a cyanohydrin compound. This can be demonstrated by the following equation:

Any suitable source of cyanide ion can be employed as a reactant, such as KCN, NaCN, NH CN. HCN, Ca(CN) The amount of cyanide which is used will depend on the amount of carbonyl groups present and should be at least equimolar with the amount of carbonyl groups and preferably in slight excess. For example, about 10% excess of cyanide ions, can be added. Preferably, the reaction is performed in aqueous solution, but it can also be performed in highly polar organic solvents such as pyridine. The reaction with the cyanide. ion is suitably carried out at a pH of from 7 to 1, preferably at a pH of about 9. The reaction temperature may vary but a temperature ranging from about 20C to about 50C is usually acceptable. The reaction rate increases with the temperature, but at temperatures above about 50C the cyanide reactant may be hydrolysed. i

The cyanide product from equation l above is then acidified in accordance with the following equation:

acidification in this acidification step, the pH is lowered to a value below 7. Any suitable acid, such as HCl and H SO can be used. The acidification can be carried out at a temperature from 0C up to the boiling point of the reaction mixture. The choice of reaction conditions H OH Hydrolysis is known in the art. It can be carried out either by heating the reaction mixture with simultaneous bubbling of air on nitrogen through the solution, or the hydrolysis can be carried out by addition of a suitable acid, such as HCl or H 80 Preferably the hydrolysis is performed by heating the reaction solution to a temperature between about 90to 100C.

In alternative methods, the acidification and hydrolysis in aforementioned equations (2) and (3), respectively, can occur almost simultaneously. The reaction product obtained in equation (l) above can be hydrolysed directly. If desired, however, the hydrolysis may be facilitated by removing, for example by ion exchange, any excess of cyanide ions before the hydrolysis.

The reaction product obtained from hydrolysis can be used directly for the preparation of the iron complex.

1n the polymerization reaction according to the present invention a mixture of reaction products with widely varying molecular weights is obtained. It is not possible to ascribe a precise, unitary chemical structure to the reaction products. The molecular weight distribution of the immediate reaction product obtained after the polymerization process is completed may as indicated above, be changed, by removing low molecular weight components. For characterizing the product, therefore, the terms and methods described herebelow have been used. The expression final product" used herebelow denotes the polymer product obtained after the working up procedure, including the optional addition of water as mentioned above.

A. Loss of Weight on Drying This is obtained by drying the final product at about 105C. until constant weight is obtained. The loss of weight is given in percent by weight calculated on the final product.

B. Content of Water in the Final Product This is determined by the Karl Fischer method which is described inter alia in Pharmacopoeia Nordica volume 1 page 75. The content of water is given in percent by weight calculated on the final product.

C. Content of Sodium (Na) in the Final Product This is determined using a flame spectrophotometer and given in percent by weight calculated on the final product in dried form.

D. Content of Chloride Ions (Cl) in the Final Product This is determined by potentiometric titration and is given in percent by weight calculated on the final product or on the final product in dried form. The amount of Na and Cl which are given indicate the amount of salts present in the polymer preparation and do not mean that chloride ions are present in the polymer molecule.

E. Content of Organic Dry Substance in the Final Product This is calculated as the weight of the final product excluding the loss of weight on drying and excluding the weight of Na and Cl and is given in grams or in percent by weight calculated on the final product.

F. Gel filtration The molecular weight distribution of the final product is estimated by gel filtration on Sephadex G115. G225 or G250. A sample consisting of an amount of final product corresponding to about 100 mg. of organic dry substance is dissolved in 4 ml. of water, added to the column of Sephadex used and eluted with water. The eluate is analyzed for content of organic dry substance by measuring the extinction at 700 mp. of a mixture of 0.5 ml. eluate and 5 ml. of a solution of 0.8 g.K Cr O in 10 m1.1-l O and 200 ml. conc. H SO4. The extinction measured is corrected against a blank and plotted against the volume of eluate. The diagram obtained is a measure of the molecular weight distribution. The eluate is also tested for contents of C 1. This gel filtration test is well known in the art as evidenced by Sephadex, Theory and Experimental Technique" published by Pharmacia Fine Chemicals, Uppsala, Swe den.

G. Content of Carboxylic Groups in the Final Solutlon This is determined by passing aqueous solution of polymer through strongly acidic cation exchanger and titrating for total contents of acid with NaOH.

H. lron-Complex-Forming Capacity of the Final Product This may be determined by using the following solutlOl'lSI 90 ml. 1.20 mole) 148 ml. (0.90 mole] Distilled water Lactic acid Sodium hydroxide Polymer (organic dry substance) 202.5 g. (ll) Sodium hydroxide 288 g. (7.3 mole) Distilled water llllll ml.

Ferric chloride hexahydrate FeCl .,.6H. ,O

270 g. 1.0 mole) percent) about 14.8 ml.

Separate solutions of the ferric chloride, the sodium hydroxide and the polymer were prepared. The lactic acid (90 ml.), 2/3 of the volume of water 150 ml.) and the sodium hydroxide 148 ml.) were mixed separately before the polymer was added. The rest of the water ml.) was used for rinsing the vessels whereafter it was added to the solution. The mixture (1) thus obtained was heated to C with stirring.

To the mixture (1) were added alternately with vigorous stirring 9 X ml. portions of the sodium hydroxide solution (11). in total 4.86 mole NaOH, and 9 X 60 ml. portions of the ferric chloride solution (Ill in total 1.0 mole. The addition was carried out dropwise during 1 minute for the sodium hydroxide and dropwise during 2 minutes for the ferric chloride solution. Between each addition a delay of 2 minutes was made. One minute after the final addition of ferric chloride solution, 167 ml. (0.98 mole) of sodium hydroxide (II) was added. The temperature of the reaction mixture was thereafter kept at 80C. for 35 minutes, whereafter the mixture was cooled to 25C. Thereafter, the volume of the reaction mixture was adjusted to 2250 ml. using distilled water, whereupon 5100 ml. ethanol was added during l530 minutes with vigorous stirring. Thereafter, the stirring was continued for minutes more. The precipitate obtained was allowed to settle for 30-60 minutes, after which the mother liquor was sucked off. The precipitate was filtered ofiand washed once with 900 ml. diluted ethanol (2 volumes of ethanol 1 volume of distilled water). Thereafter, the precipitate was dissolved by adding it while stirring to 1350 ml. of distilled water heated to 40C. After addition of the precipitate, the solution was heated to 80C. in about 30 minutes. Thereafter, the mixture was kept at 80C. while stirring for 30 minutes more.

The solution was thereafter cooled to 25C. and neutralized using 6N hydrochloric acid 1V added dropwise with vigorous stirring during 35 minutes until the pH of the mixture was 6.2. Usually, l40150 ml. of hydrochloric acid was necessary. The reaction mixture was freed from undissolved matter, whereafter the volume was adjusted with distilled water (V) to 2100 ml. A second precipitation was carried out by adding to the solution with stirring 4575 ml. of ethanol (VI) during 15-20 minutes. Stirring was continued for 2 minutes more. The precipitate was allowed to settle overnight. Thereafter. the mother liquor was sucked off and the solid was sucked off and washed three times using 900 ml. of diluted ethanol (ethanol: water 2:1) and three times with undiluted ethanol (900 ml.), whereafter it was dried in vacuum at 40C. for 45 hours or overnight.

The following parameters were determined in the dried iron preparation:

1. Yield of dried iron preparation, measured in grams.

2. Yield of complex-bound iron, calculated in percent of the total amount of ferric iron added during the reaction.

3. Contents of iron in the dried iron preparation, percent by weight calculated on the dried iron preparation.

1. Resorption in Rabbit of lntramuscularly Administered Injection Solution The injection solution of the dried iron preparation obtained as described in paragraph H above was prepared according to the following method. Distilled water (125 ml.) was heated to 80C. in a 3-necked round-bottomed flask provided with cooler, thermometer and stirrer. Dried iron preparation obtained as de scribed above was added in small portions during 15 minutes with vigorous stirring. Dried preparation corresponding to 7.5 g. of iron was added. The solution thus obtained was kept at 80C. for 50 minutes, whereafter it was cooled to C. After dilution with distilled water to 150 ml. the solution obtained was filtered, filled into 10 ml. ampoules and sterilized at 120C. for 20 minutes. The injection solution obtained had a total content of iron of about 50 mg/ml.

The resorption tests on rabbits were carried out in the following way. The injection solution was injected in doses of 20 mg. Fe per kg. body weight deep into the glutei of rabbits. Male albino rabbits weighing 2 to 3 kg. were consistently used. The animals were killed at different time intervals after injection and the gluteal muscles were dissected away from the leg. Musculature and skin around the injection site were wet oxidized with sulphuric acid and nitric acid, and the iron content was then determined by means of a colorimetric rhodanide method. It was found that the iron was resorbed very rapidly. In most cases, more than 60% of the administered iron had been resorbed after 24 hours; more than of the iron had been resorbed after 7 days; and more than of the iron had been resorbed after 14 days. It was also found that the amount of iron which was excreted after 24 hours usually was less than 15%. Thus, it is shown that iron preparations for intramuscular injection prepared using the polymer of the present invention as stabilizing agent compare favorably with presently existing and marketed intramuscularly administrable iron preparations. It can be concluded from the results of gel filtration on Sephadex G115, G225 and 0:50 gels that the average molecular weight of the polymer in the form called final product" is in the range 700 to about 5000. It has also been established that polymers, which according to gel filtration tests have an average molecular weight in the range from about 1500 to about 5000, provide iron complexes, which in the form of injection solutions, give a particularly advantageous response with regard to resorption and excretion when tested on rabbits.

J. Intrinsic Viscosity of the Polymer This in many cases was found to be in the range from about 0.020 to about 0.080 dl/g. It is determined according to well known procedures [Flory, Principles of Polymer Chemistry (1953)].

Thus, in accordance with the present invention a new polymer has been prepared which a. is soluble or swellable in water;

b. is physiologically innocuous;

c. has capability of reacting with polyvalent metal cations such as Fe, Al Cr, Sb, Bi, Zr, Sn, Ti, Bi and Ca, or mixtures thereof, with formation of a complex between the polymer and the metal cation; and

d. has the capability of stabilizing ferric iron in aqueous solutions intended for intramuscular or intravenous injection of mammals including man.

The preferred embodiment of the invention, is the polymer built up by sucrose, sorbitol and epichlorohydrin, and furthermore e. contains from about 0.2 to about 1.5 milliequiva [cuts of carboxyl groups per gram organic dry substance,

f. has an average molecular weight, as estimated by gel filtration, in the range from about 700 to about 5000.

The polymer of the present invention is particularly valuable and useful as a stabilizing agent for iron preparations intended for intramuscular injection. The use of the polymer as such a stabilizing agent is an important aspect of the present invention. The polymer may be also used. among other uses, as

a. a viscosity regulating agent in foodstuffs, pharmaceuticals, herbicides and similar preparations, or in washing agents;

b. a substitute for blood plasma;

c. a carrier substance for biologically active substances such as enzymes.

d. a polymer metal ion complex as a soil improving material;

e. a liquid cement or glue;

f. a starting material in the preparation of plastic materials;

g. a precipitation or flocculation inhibiting agent in the production of beer;

h. an additive to electrolytes;

i. a detoxifying agent.

13 j. in combination with suitable substances, such as Ba, used as an X-ray contrast agent.

Another embodiment of this invention is iron preparations for intramuscular injection wherein the aforementioned polymer is used as stabilizing agent. A dry iron-containing composition which can be worked up into a preparation suitable for intramuscular injection in human and veterinary medicine is prepared by reacting in alkaline aqueous solution;

a. at least one water-soluble, ferric salt and b. a physiologically innocuous, water swellable polymer prepared as described previously and capable of forming complexes with ferric iron at an alkaline pH, whereafter the iron-containing complex is precipitated and the precipitate is purified and dried. The reaction between the ferric salt and the polymer is carried out at a pH to provide, by addition of alkali, at the end of the reaction a pH of about to l4.

The invention also includes liquid iron-containing compositions comprising an aqueous solution of the dry iron-containing composition obtained as described above. The compositions are readily soluble at physiological pH values and are sufficiently stable for the solutions to be sterilized by autoclaving.

The iron must be in the trivalent form since ferrous compounds do not give the desired stability. Suitable ferric compounds, among others, include ferric chlo ride, ferric nitrate, ferric sulphate and ferric acetate, and double salts (e.g., ferric ammonium sulphate and ferric potassium sulphate) and mixtures thereof.

The dried compositions may contain from about to 40%, especially about 20% to 36%, by weight of iron and the injectable solutions may contain from about 5 to about I00 milligrams of iron per milliliter, especially about 50 milligrams of iron per milliliter. it is generally desirable that the iron concentration in the injection solution should be as high as possible, in order that the injected volume may be small. In some cases, however, less concentrated preparations may be more suitable.

The polymer used as stabilizing agent in the iron preparations is preferably built up by reacting, in the manner described herein, at least one saccharide selected from the group consisting of sucrose, trehalose and rafiinose, at least one polyhydric alcohol selected from the group consisting of glycerol, polyglycerols, tetritols, pentitols, hexitols, heptitols, and hydroxyloweralkyl, hexitols and heptitols derived therefrom, at least one polymerizing agent selected from the group consisting of epichlorohydrins and diepoxides. The preferred polymer is built up by sucrose, sorbitol, and epichlorohydrin as previously described.

The dry iron preparation is prepared by reacting in aqueous solution a polymer prepared as described previously, with the aforementioned water-soluble ferric compound, preferably ferric chloride, whereafter the iron-containing complex thereby obtained is precipitated and the precipitate is purified and, if desired, dried. The pH of the reaction mixture is adjusted to provide a value of about l0 to 14 at the end of the reaction. The amount of polymer used in the reaction may be in the range from about i to about 15 g., preferably from about 3 to about 6 g., calculated as dried product per gram of iron, depending on the particular polymer used. The reaction temperature suitably is in the range from about 0C. to about lO0C. depending on the particular embodiment used. in the first embodiment described herebelow, the temperature is preferably at about C. The pH of the acidic reaction mixture is successively increased during the reaction to a value of about 10 to 14. As the alkali, sodium hydroxide may advantageously be used. The precipitation of the iron complex from the reaction solution is effected using a nonsolvent for the complex. Ethanol is used suitably. If the solution of the iron complex is to be used directly, the complex is not precipitated after the final dissolution.

Besides water-soluble ferric compounds, ferric compounds which are slightly or very slightly soluble in water may be used, for example, freshly prepared ferric hydroxide, ferric carbonate and ferric lactate.

For purification of the precipitate, redissolution is conveniently carried out by adding the precipitate to distilled water at a temperature of about 40C. The temperature is Subsequently raised to about 80C.. and kept there for some time. Thereafter, the solution is cooled to room temperature and the pH is adjusted from about 5.5 to about l0, preferably to about 6 to about 8, with a suitable acid, such as HCl.

in one embodiment of the process for preparing the dry iron preparation, an alkaline aqueous solution of the polymer, and optionally lactic acid, is prepared. Lactic acid may be added in an amount from 0 to about l0 g. per gram of iron. The mixture is thereafter heated to about 80C. and portions of the ferric compound in aqueous solution and portions of alkali in aqueous solution are interchangeably added. In this way, the pH of the reaction mixture is consistently kept alkaline. The polymer is added in an amount corresponding to from about I to about 15 g. calculated as dried substance, per gram of iron. Preferably, from about 3 to about 6 g. of polymer, calculated as dried product, are used per gram of iron. The reaction mixture may thereafter be allowed to stand for some time and thereafter cooled to room temperature. The iron complex formed is thereafter precipitated using a non-solvent for the complex, suitably ethanol. The precipitate formed is separated. It is purified by repeated dissolution in water, precipitation and washing. It is finally dried.

In another embodiment of the process for preparing the dry iron preparation. a first aqueous solution containing the polymer and the total amount of the ferric salt to be used is prepared. From about I to about 15 g. of polymer per gram iron is used in said first aqueous solution. The preferred ratio is from about 3 to about 6 g. polymer per g. iron. To the acidic solution thus ob tained, to which lactic acid suitably is not added, alkali is successively added at a suitable temperature in the range of from about 0 to 60C. When all alkali has been added, the temperature of the reaction mixture is raised to about 80C., kept there for some time, and subsequently lowered to about 25C. The iron complex formed is thereafter worked up by precipitation and redissolution as described previously, with the excep tion that some further polymer in alkaline aqueous solution is suitably added at each redissolution. For example, if two precipitations and redissolutions are carried out, about one fourth of the amount of initially added polymer may be added during each redissolution.

When preparing an injection solution of the dry iron preparation, the dry iron preparation is dissolved in water and sterilized by autoclaving. The dry iron preparation is added in portions, with stirring, to distilled water at a temperature of about 80C. When all the dry iron composition has been added, the temperature is kept at 80C. for some additional time. for example, about 50 minutes, whereafter the solution is cooled to about C., optionally diluted with distilled water, filtered, and filled in bottles which are autoclaved at about 120C. for about 20 minutes. A typical prepara tion thus obtained contains about 5 to 100. e.g., 50, mg. iron per ml.

As is evident from the following examples, the iron As shown in Table l, materials were added in the following portions: 85 g. NaOH in solid form; 20 g. NaOH dissolved in distilled water to a volume of28 ml. and 55 ml. epichlorhydrin.

Furthermore, 250 ml. benzene and 200 ml. distilled water were added because of the increasing viscosity of the reaction mixture during the course of the reaction.

preparations in the form of sterilized injection solutions are well resorbed when tested on rabbits, while at the same time the excretion of iron is low, often less than 15% 24 hours after the administration. The acute i.p. toxicity in mice of the injectable iron preparations has been found to be in the range 300 to 500 mg. per kg. of bodyweight. The acute i.p. toxicity in mice of Jectofer as tested on the same strain of mice is about mg per kg. of bodyweight. The low toxicity of the iron preparation according to the present invention in combination with its high resorption and low excretion makes it possible to administer it to human patients in unit dosages containing more than 500 mg. iron. Two such dosages may be given to each patient at a single occasion.

The correlation of test results in this field between the treatment of animals, e.g., rabbits, and the treat ment of human beings is substantiated in the art as evidenced by Lindvall, Andersson, Studies on a New Intramuscular Haemativic Iron-sorbitol", British .lournal of Pharmacology and Chemotherapy, 17, 358371 (1961) and Andersson Clinical Investigations on a New Intramuscular Haematic". British Medical Journal, 275-279 (July 29, 1961).

The invention is illustrated further by the following examples.

EXAMPLE 1 To a round-bottomed flask, volume 5 liter, provided with stirrer. dropping funnel, thermometer and cooler were added at 45C.

150 ml. distilled water 34 g. NaOH 300 g. sorbitol 150 g. surcrose Then 200 ml. epichlorhydrin was added continuously during min. The temperature was raised to C. during 20 min. as calculated from the start of addition of the epichlorhydrin. The temperature of 75C. is retained during the polymerization, which is carried out with effective stirring.

At 285 min. the cooling of the reaction mixture was started simultaneously with slow addition of 50 ml. 4M HCl. ml. 6 M HCl is thereafter added whereby the polymer forms an easily removable suspension in the benzenewater mixture. AT 305 min. the temperature is 56C. in the reaction mixture and at 330 min. the cooling is stopped. The temperature is then 30C. Then 70 ml. 2 M NaOH is added and the pH is 0.0 measured after 15 min. The reaction mixture is filtered through double filter papers. The filtration which was very slow was allowed to continue over night.

The next day the filtration was finished and the filtrate had formed two phases. On the filter a small amount of an adhesive rest remains. The different fractions are defined as follows:

Filtrate, benzene phase designated as F l, discarded.

Filrate, water phase designated F 2.

Remainder on filter designated as F 3, discarded. The F 2 fraction was strongly opalescent and was therefore filtered through Zeiss filter plate Ko 2. The filtrate was still opalescent but to a considerably diminished degree compared with the opalescence before the filtering. The fractions were:

Filtrate designated as F 4. volume 1070 m1.

Remainder designated as F 5, minute amount, discarded. The F 4 fraction was diluted with water to 1200 ml. and the pH was 0.02. Then 3000 ml. ethanol, 99.5% was added with vigorous stirring whereupon the mixture was allowed to stand for 60 min. to form:

Mother liquor designated as F 6, discarded.

Remainder designated as F 7. volume 750 ml.

The F 7 fraction was mixed with ml. distilled water and 1500 ml. ethanol, 99.5%. The mixture was allowed to stand for 2 hours to provide:

Mother liquor designated as F 8.

Remainder designated as F 9, volume 650 ml.

The F 9 fraction was mixed with 325 ml. distilled water. The mixture was stirred for 10 min. and thereafter 1300 ml. ethanol, 99.571 was added. The mixture was allowed to stand for 30 min. and the fractions were as follows:

Mother liquor designated as F 10.

Remainder designated as F l l, volume 630 ml. The F ll fraction was mixed with 315 ml. distilled water and with 1260 ml. ethanol, 99.5%. whereafter the mixture was allowed to stand for 40 min. to form:

Mother liquor designated as F 12.

Remainder designated as F 13, volume 500 ml. The F 13 fraction was mixed with 100 ml. distilled water and l000 ml. ethanol, 99.5%. The mixture was allowed to stand for 30 min. to provide:

Mother liquor designated as F 14.

Remainder designated F 15. The F 15 fraction was washed three times with 150 ml. ethanol, 99.5%, whereupon it was dried in vacuum at 50C. for 60 min. in order to remove rest of the ethanol. The dried F 15 fraction was diluted with distilled water to 493 g. to form a product which was analyzed as follows;

Loss of weight at drying 32.7%.

Contents of Na 4.7% calculated on dried sample. Contents of (I 4.2% calculated on dried sample EXAMPLE 2 Solution 1 was formed from 273 g. of the product prepared in Example 1, which contained reducing groups corresponding to 18 g. glucose, 500 ml. distilled water and 0.5 ml. 25% NH OH. Solution II was provided from 15 g. KCN corresponding to the double equivalent amount of glucose plus about glucose in excess, calculated on 18 g. glucose in 50 ml. distilled water.

Solution 1 was added to a round-bottom flask provided with magnet stirrer, dropping funnel, thermometer, and cooler with receiver. Solution ll was added to solution I at room temperature and was allowed to stand for 30 minutes. Thereafter the temperature was raised to 40C. and was kept there during 120 min. The solution was then allowed to cool and was allowed to stand at room temperature for 3 days. The temperature was subsequently to 70C. in 90 min., while a stream of air simultaneously was passed through the solution. After min. at 70C. the heating was interrupted and the temperature was allowed to drop to 30C. 2 M HCl was added slowly with vigorous stirring to form a pH of about 6.

Thereafter, the solution was heated again to about 70C. during simultaneous aeration. After repeated heating and aeration, which was carried out during 60 min. the solution was allowed to cool to room temperature whereafter pH was adjusted to about 1 with 2 M HCl. The acidified solution was allowed to stand to the next day and it was then heated to 70C. during 30 min. After cooling, the solution was tested for presence of cyanide ions.

The test indicated that no cyanide ions were present. The solution was evaporated in vacuo to about half its volume whereupon the pH was adjusted to 5 using NaHCO Ten grams of active carbon was added during stirring. After [5 min. the mixture was filtered through Zeiss filter plate No. K02. The filter plate was washed with distilled water. The washing water was mixed with the filtrate and the resulting mixture was evaporated in vacuo to about 250 ml. Two volumes of ethanol. 99.5%, were added whereupon the mixture was al- 18 lowed to stand for 30 min. Thereafter two phases had formed as follows.

Light phase designated as F l.

Heavy phase designated as F 2, volume 230 ml. The F 2 phase was mixed with N5 volume distilled water and with 2 volumes of ethanol, 99.5%. The mixture was allowed to stand for 30 min., whereby 2 phases were formed as follows:

Light phase designated as F 3.

Heavy phase designated as F 4.

The F 4 phase was mixed with /2 volume distilled water and with 2 volumes of ethanol, 99.5%. The mixture was allowed to stand for 30 min. whereby the following 2 phases separated:

Light phase designated as F 5.

Heavy phase designated as F 6, volume 210 ml. The F 6 phase was mixed with 21 ml. distilled water and with 105 ml. ethanol, 995%. After 30 min. the result ing light phase (F 7) was decanted. The resulting heavy phase (F 8) was washed twice with 105 ml. ethanol, 99.5%, and three times with acetone. whereupon it was dried in vacuo in order to remove remaining rests of acetone. The dried fraction was diluted with distilled water to 231 g.

The product was analyzed as follows:

054 milliequivalents/ g. organic dry substance.

Contents of (arboxyl groups EXAMPLE 3 This example is concerned with the preparation of a dry iron preparation.

The polymer of Example 2 corresponding to 60 g. of organic dry substance was dissolved in 300 ml. of distilled water at room temperature. A solution containing 60 g. FeCl -,.6HO in 100 ml. of distilled water was mixed with the polymer solution at room temperature. To the mixture obtained was added under stirring 1000 ml. 1M NaOH. After minutes at room temperature, the temperature of the mixture was raised to C. The mixture was kept at this temperature for 20 minutes whereupon it was cooled to room temperature and filtered through Seitz filter plate K02. The filtrate was diluted with distilled water to 1900 ml. whereafter 3800 ml. 99.5% ethanol was added under vigorous stirring. After 20 minutes, the precipitate obtained was filtered off and dissolved in a mixture of 600 ml. distilled water, 15 g. polymer calculated as organic dry substance, and 20 ml. 1M NaOH. The temperature was raised to 80C. and kept there for 25 minutes, whereafter the solution was cooled to room temperature. To the cooled solution lM HCl was added with vigorous stirring until a pH of 6.7 was obtained. The solution was filtered through Seitz filter plate EKS. The filter plate was washed with distilled water, which was mixed with the filtrate. The pH of the mixture was adjusted from 7.7 to 7.3 using 1M HCl. The volume was then adjusted with distilled water to 1000 ml. and 2000 ml. ethanol, 99.5%, was added with vigorous stirring. After 30 minutes the precipitate obtained was filtered off and washed with ml. ethanol diluted to the same con- 19 centration as the mother liquor and with 100 ml. ethanol diluted to 75% and finally three times with 150 ml. ethanol, 99.5%. The washed precipitate was dried in vacuum at 50C.

The yield was 74 g. The total content of Fe was 22.8% calculated on the original sample.

EXAMPLE 4 In this example an injection solution was prepared.

To a round-bottomed flask, volume 500 ml. provided with stirrer, thermometer and cooler, 130 ml. distilled water was added and heated to 80C. Then 32.9 g. of the dry iron preparation of Example 3 was added to the water for 10 min. with stirring. The temperature of the mixture was kept at 80C. for 70 min. calculated from the start of addition of the dry iron preparation. The solution obtained was cooled thereafter to room temperature and the pH was adjusted to 7.6

using lM HCl. The volume was adjusted subsequently h to 150 ml. with distilled water. The solution was there after filtered through Zeiss filter plate K02 and through Pyrex glass filter. The filtrate was filled on ampoules and autoclavated at 120C for 20 min.

Analysis.

Total amount of Fe 50.5 mg/ml Amount of Fo 98 mg/ml VISCUSil) 10.7 cPs pH 7.7

The resorption of Fe from rabbit muscle after 7 days was 86%. The excretion of Fe in the urine of the rabbit during the first 24 hours after the injection was 2%.

Having set forth the general nature and specific embodiments of the present invention, the scope is now particularly pointed out in the appended claims.

What is claimed is:

l. A composition for treatment of iron deficiency by parenteral administration comprising an aqueous solution of a complex of ferric iron, said complex containing ferric iron which is bound to a polymer wherein said complex is prepared by A. reacting in an aqueous solution at a temperature between about 20C and the boiling point of the reaction mixture 1. about 0.1 to 1.0 moles ofa saccharide (per mole of component (3) below) which is selected from the group consisting of a. sucrose. b. trehalose, and c. raffinose;

2. about 0.05 to moles of a polymerization agent (per mole of component (3) below) of the formula wherein n is an integer selected from the group consisting of O, l. 2. 3 and 4; X is selected from the group consisting of Cl, Br. and l; R is selected from the group consisting of OH, Cl, Br, and l; and R is selected from the group consisting of H and CH X with the proviso that R is CH X only when R is OH, wherein X has the meaning specified above; the epoxides or the diepoxides derivable therefrom; and 3. a hexitol selected from the group consisting of sorbitol. hydroxypropyl sorbitol, mannitol, tali- 5 to], iditol, galactitol, and allitol to form a first intermediate of the formula lpolymcrI C U I;

B. reacting said first intermediate product with a cyanide selected from the group consisting of KCN, NaCN, Ca(CN) HCN. and NH CN in an amount at least equimolar with the amount of carbonyl groups on the first intermediate product to form a second intermediate product of the formula (pulymcr) C-CN C. acidifying said second intermediate product to form a third intermediate product of the formula OH Ill;

D. hydrolyzing said third intermediate product to form a water swellable polymer of the formula (polymcr) C\COOH on w;

and E. reacting said water swellable polymer with a ferric compound in solution under alkaline conditions to form said complex of ferric iron.

2. A composition according to claim 1 wherein the polymerization agent is selected from the group consisting of (a) (H2 CH(CH2),,CH-CH v;

x m AM (h) CH,--CH---(CH I,,-CH--CH VI; 0 o

(c) CH2-TH-CH. vu;

(a CH. CH--CH- ,X vm;

(c) TH -CHACH J ATH and IX; X OH in CH. -CHtCH- j H XI wherein n is an integer selected from the group consisting of 0, 1 2. 3 and 4, and X is selected from the group consisting of Cl, Br and l.

3. The composition according to claim 1, in which the ferric iron is derived from a compound selected from the group consisting of:

a. ferric chloride,

b. ferric nitrate,

c. ferric sulfate,

d. ferric acetate.

e. double salts thereof.

4. The composition according to claim 1, in which the ferric iron is derived from ferric chloride.

5. The composition according to claim I which contains about to 40% iron.

6. A composition according to claim 1 wherein the polymerization agent is a structure V compound wherein X is Cl.

7. A composition according to claim 1 wherein the polymerization agent is a structure Vlll compound wherein X is Cl.

8. A composition according to claim I wherein the polymerization agent is a structure Vlll compound wherein X is Br.

9. A composition according to claim I wherein the polymerization agent is a structure Xl compound wherein n is 0.

10. A composition according to claim 1 wherein the polymerization agent is a structure Vll compound wherein X is Cl.

11. A composition according to claim 1 wherein the hexitol is sorbitol.

12. A composition according to claim 1 wherein the hexitol is galactitol.

13. A composition according to claim I wherein the hexitol is mannitol.

14. A composition according to claim 1 wherein trehalose is the saccharide, sorbitol is the hexitol and epichlorohydrin is the polymerization agent.

15. A composition according to claim 1 wherein raffinose is the saccharide, sorbitol is the hexitol, and epichlorohydrin is the polymerization agent.

16. A composition according to claim I wherein sucrose is the saccharide, mannitol is the hexitol, and epichlorohydrin is the polymerization agent.

17. A composition according to claim I wherein sucrose is the saccharide, galactitol is the hexitol, and epichlorohydrin is the polymerization agent.

18. A composition according to claim I wherein sucrose is the saccharide, hydroxypropylsorbitol is the hexitol, and epichlorohydrin is the polymerization agent.

19. A composition according to claim 1 wherein sucrose is the saccharide, sorbitol is the hexitol, and epichlorohydrin is the polymerization agent.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. 1 3,928,581

DATED 1 December 23, 1975 INVENTOWS) 1 Alf-Goran Dahlberg et al.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 6, lines 25-28,

Column 21, claims 6-10, line 1 of each claim, delete "claim 1'' and substitute therefor claim 2 Signed and Scaled this Twenty-fourth Day of August 1976 [SEAL] Anew:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner ufParems and Trademarks 

1. A COMPOSITION FOR TREATMENT OF IRON DEFICIENCY BY PARENTERAL ADMINISTRATION COMPRISING AN AQUEOUS SOLUTION OF A COMPLEX OF A FERRIC IRON, SAID COMPLEX CONTAINING FERRIC IRON WHICH IS BOUND TO A POLYMER WHEREIN SAID COMPLEX IS PREPARED BY A. REACTING IN AN AQUEOUS SOLUTION AT A TEMPERATURE BETWEEN ABOUT 20*C AND THE BOILING POINT OF THE REACTION MIXTURE
 1. ABOUT 0.1 TO 1.0 MOLES OF A SACCHARIDE (PER MOLE OF COMPONENT (3) BELOW) WHICH IS SELECTED FROM THE GROUP CONSISTING OF A. SUCROSE, B. TREHALOSE, AND C. RAFFINOSE;
 2. ABOUT 0.05 TO 5 MOLES OF A POLYMERIZATION AGENT (PER MOLE OF COMPONENT (3) BELOW) OF THE FORMULA
 2. A composition according to claim 1 wherein the polymerization agent is selected from the group consisting of
 2. about 0.05 to 5 moles of a polymerization agent (per mole of component (3) below) of the formula
 3. A HEXITOL SELECTED FROM THE GROUP CONSISING OF SORBITOL HYDROXYPROPYL SORBITOL, MANNITOL, TALITOL, IDITOL, GALACTITOL, AND ALLITOL TO FORM A FIRST INTERMEDIATE OF THE FORMULA (POLYMER)>C=O B. REACTING SAID FIRST INTERMEDIATE PRODUCT WITH A CYANIDE SELECTED FROM THE GROUP CONSISTING OF KCN,NACN CA(CN)2, HCN, ANDNH4CN IN AN AMOUNT AT LEAST EQUIMOLAR WITH THE AMOUNT OF CARBONYL GROUPS ON THE FIRST INTERMEDIATE PRODUCT TO FORM A SECOND INTERMEDIATE PRODUCT OF THE FORMULA (POLYMER)>C(-CN)-O(-) C. ACIDIFYING SAID SECOND INTERMEDIATE PRODUCT TO FORM A THIRD INTERMEDIATE PRODUCT OF THE FORMULA (POLYMER)>C(-CN)-OH D. HYDROLYZIING SAID THIRD INTERMEDIATE PRODUCT OT FORM A WATER SWELLABLE POLYMER OF THE FORMULA (POLYMER)>C(-COOH)-OH AND E. REACTING SAID WATER SWELLABLE POLYMER WITH A FERRIC COMPOUND IN SOLUTION UNDER ALKALINE CONDITIONS TO FORM SAID COMPLEX OF FERRIC IRON.
 3. The composition according to claim 1, in which the ferric iron is derived from a compound selected from the group consisting of: a. ferric chloride, b. ferric nitrate, c. ferric sulfate, d. ferric acetate, e. double salts thereof.
 3. a hexitol selected from the group consisting of sorbitol, hydroxypropyl sorbitol, mannitol, talitol, iditol, galactitol, and allitol to form a first intermediate of the formula (polymer)>C 0 I; B. reacting said first intermediate product with a cyanide selected from the group consisting of KCN, NaCN, Ca(CN)2, HCN, and NH4CN in an amount at least equimolar with the amount of carbonyl groups on the first intermediate product to form a second intermediate product of the formula
 4. The composition according to claim 1, in which the ferric iron is derived from ferric chloride.
 5. The composition according to claim 1 which contains about 5 to 40% iron.
 6. A composition according to claim 1 wherein the polymerization agent is a structure V compound wherein X is Cl.
 7. A composition according to claim 1 wherein the polymerization agent is a structure VIII compound wherein X is Cl.
 8. A composition according to claim 1 wherein the polymerization agent is a structure VIII compound wherein X is Br.
 9. A composition according to claim 1 wherein the polymerization agent is a structure XI compound wherein n is
 0. 10. A composition according to claim 1 wherein the polymerization agent is a structure VII compound wherein X is Cl.
 11. A composition according to claim 1 wherein the hexitol is sorbitol.
 12. A composition according to claim 1 wherein the hexitol is galactitol.
 13. A composition according to claim 1 wherein the hexitol is mannitol.
 14. A composition according to claim 1 wherein trehalose is the saccharide, sorbitol is the hexitol and epichlorohydrin is the polymerization agent.
 15. A composition according to claim 1 wherein raffinose is the saccharide, sorbitol is the hexitol, and epichlorohydrin is the polymerization agent.
 16. A composition according to claim 1 wherein sUcrose is the saccharide, mannitol is the hexitol, and epichlorohydrin is the polymerization agent.
 17. A composition according to claim 1 wherein sucrose is the saccharide, galactitol is the hexitol, and epichlorohydrin is the polymerization agent.
 18. A composition according to claim 1 wherein sucrose is the saccharide, hydroxypropylsorbitol is the hexitol, and epichlorohydrin is the polymerization agent.
 19. A composition according to claim 1 wherein sucrose is the saccharide, sorbitol is the hexitol, and epichlorohydrin is the polymerization agent. 